fix: serve design studio through the component app production route

test/hosted-studio.test.ts

@@ -1,6 +1,30 @@
 import { expect, test } from "bun:test";
 import { createStudioHandler } from "@wrnexus/design-studio/server";
 import { CORE_DESIGN_SYSTEMS } from "@wrnexus/design-system";
+import { createContext } from "@wrnexus/core";
+import designStudio from "../app/middleware/design-studio.ts";
+
+test("application middleware mounts Studio before unmatched routes and preserves normal pages", async () => {
+  const send = (path: string) => {
+    const req = new Request("https://components.example" + path);
+    return designStudio(
+      createContext(req, new URL(req.url)),
+      () => new Response("normal page"),
+    );
+  };
+  expect(await (await send("/components/button")).text()).toBe("normal page");
+  expect(await (await send("/design-studio-other")).text()).toBe("normal page");
+  const redirect = await send("/design-studio");
+  expect(redirect.status).toBe(308);
+  expect(redirect.headers.get("location")).toBe("/design-studio/");
+  expect(await (await send("/design-studio/")).text()).toContain(
+    "WrNexus Design Studio",
+  );
+  expect((await send("/design-studio/studio.js")).status).toBe(200);
+  expect(
+    (await (await send("/design-studio/api/application")).json()).enabled,
+  ).toBe(false);
+});
 
 test("deployed Studio serves assets and isolated previews without application writes", async () => {
   const handler = await createStudioHandler({